1) Field of the Invention
The invention relates to a device for detecting small quantities of light, comprising optical detection means for detecting the photons representing the small quantities of light and an electronic circuit connected to the optical detection means for reading the optical detection means and for generating a signal representing the number of photons received by the optical detection means.
2) Description of the Related Art
Such devices are generally known. Such prior art detection devices make use of, among other parts, a photon multiplier tube, an expensive, heavy and fragile apparatus which requires a high supply voltage and which is therefore less suitable for use in the field.
In order to obviate these drawbacks the dissertation by Khaled Salama, Stanford University, September 2005, “Cmos-luminescence detection lab-on-chip modeling, design and characterisation”, provides a device for the detection of small quantities of light, comprising an electronic image converter embodied in semiconductor technology for detecting the photons representing the small quantities of light and an electronic circuit connected to the electronic image converter for reading the electronic image converter and for generating a measurement signal representing the number of photons received by the electronic image converter.
This prior art device avoids the technical problems associated with photon multiplier tubes, such as a high supply voltage and a fragile construction.
It has however been found that, when such a device is optimized to an optimal sensitivity to light, this sensitivity is greatly influenced by the temperature. This influence is so great that the prior art device can hardly be used outside laboratory conditions. It is however the intention to use the device according to the invention in practice, i.e. outside the laboratory, at usually varying temperatures. The object of the invention is to provide such a device which—while retaining a high sensitivity to light—is as insensitive as possible to temperature.